(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    //define([], factory);
    define([], factory());
  } else if (typeof module === 'object' && module.exports) {
    // Node. Does not work with strict CommonJS, but
    // only CommonJS-like environments that support module.exports,
    // like Node.
    module.exports = factory();

  } else {
    // Browser globals (root is window)
    root['watermark'] = factory();
  }
}(this, function () {

  // Just return a value to define the module export.
  var watermark = {};

  // 加载水印
  var loadMark = function (settings) {
    var defaultSettings = {
      watermark_id: 'wm_div_id',          //水印总体的id   
      watermark_zIndex: '999999',          //水印总体的层级  
      watermark_position: 'absolute',          //水印总体的模式 跟随文档流(absolute)或 固定(fixed)
      watermark_prefix: 'mask_div_id',    //小水印的id前缀
      watermark_txt: "代用名 GA0088XX 100.255.255.360",             //水印的内容
      watermark_x: 100,                     //水印起始位置x轴坐标
      watermark_y: 100,                     //水印起始位置Y轴坐标
      watermark_rows: 0,                   //水印行数
      watermark_cols: 0,                   //水印列数
      watermark_x_space: 80,              //水印x轴间隔
      watermark_y_space: 80,               //水印y轴间隔（20190924修改，还原值80）
      watermark_font: '微软雅黑',           //水印字体
      watermark_color: '#58728E',            //水印字体颜色
      watermark_fontsize: '14px',          //水印字体大小
      watermark_lineHeight: '40px',          //水印行高（20191201修改，还原值20）
      watermark_alpha: 0.3,               //水印透明度，要求设置在大于等于0.005
      watermark_width: 320,                //水印宽度（20191201修改，还原值220）
      watermark_height: 135,               //水印长度（20191201修改，还原值100）
      watermark_angle: 30,                 //水印倾斜度数
      watermark_parent_width: 0,      //水印的总体宽度（默认值：body的scrollWidth和clientWidth的较大值）
      watermark_parent_height: 0,     //水印的总体高度（默认值：bodys的scrollHeight和clientHeight的较大值）
      watermark_parent_node: null     //水印插件挂载的父元素element,不输入则默认挂在body上
    };

    //采用配置项替换默认值，作用类似jquery.extend
    if (arguments.length === 1 && typeof arguments[0] === "object") {
      var src = arguments[0] || {};
      for (key in src) {
        if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key])
          continue;
        //veronic: resolution of watermark_angle=0 not in force
        else if (src[key] || src[key] === 0)
          defaultSettings[key] = src[key];
      }
    }

    //如果元素存在则移除
    var watermark_element = document.getElementById(defaultSettings.watermark_id);
    if (watermark_element) {
      var _parentElement = watermark_element.parentNode;
      if (_parentElement) {
        _parentElement.removeChild(watermark_element);
      }
      //document.body.removeChild(document.getElementById(defaultSettings.watermark_id));
    }


    //获取页面最大宽度
    var page_width = Math.max(document.body.scrollWidth, document.body.clientWidth) - defaultSettings.watermark_width / 2;
    //获取页面最大长度
    var page_height = Math.max(document.body.scrollHeight, document.body.clientHeight, document.documentElement.clientHeight) - defaultSettings.watermark_height / 2;

    var setting = arguments[0] || {};
    var parentEle = defaultSettings.watermark_parent_node;

    var page_offsetTop = 0;
    var page_offsetLeft = 0;


    if (setting.watermark_parent_width || setting.watermark_parent_height) {
      setting.watermark_parent_width ? (page_width = setting.watermark_parent_width - defaultSettings.watermark_width / 2) : (defaultSettings.watermark_parent_node) ? (page_width = parentEle.offsetWidth - defaultSettings.watermark_width / 2) : void 0;
      setting.watermark_parent_height ? (page_height = setting.watermark_parent_height - defaultSettings.watermark_height / 2) : (defaultSettings.watermark_parent_node) ? (page_height = Math.max(parentEle.offsetHeight, parentEle.scrollHeight) - defaultSettings.watermark_height / 2) : void 0;

      //指定父元素同时指定了宽或高
      if (parentEle) {
        // page_offsetTop = parentEle.offsetTop || 0;
        // page_offsetLeft = parentEle.offsetLeft || 0;
        //  @2018-05-15 修复水印指定父元素挂载的bug
        page_offsetTop = $(parentEle).offset().top || 0;
        page_offsetLeft = $(parentEle).offset().left || 0;
        defaultSettings.watermark_x = defaultSettings.watermark_x + page_offsetLeft;
        defaultSettings.watermark_y = defaultSettings.watermark_y + page_offsetTop;
      }
    } else {
      if (parentEle) {
        // page_offsetTop = parentEle.offsetTop || 0;
        // page_offsetLeft = parentEle.offsetLeft || 0;
        //  @2018-05-15 修复水印指定父元素挂载的bug
        page_offsetTop = $(parentEle).offset().top || 0;
        page_offsetLeft = $(parentEle).offset().left || 0;
        page_width = parentEle.offsetWidth - defaultSettings.watermark_width / 2 || 0;
        page_height = (Math.max(parentEle.offsetHeight, parentEle.scrollHeight) - defaultSettings.watermark_height / 2) || 0;

        defaultSettings.watermark_x = defaultSettings.watermark_x + page_offsetLeft;
        defaultSettings.watermark_y = defaultSettings.watermark_y + page_offsetTop;
      }
    }

    //创建水印外壳div
    var otdiv = document.getElementById(defaultSettings.watermark_id);
    var shadowRoot = null;

    if (!otdiv) {
      otdiv = document.createElement('div');

      //创建shadow dom
      otdiv.id = defaultSettings.watermark_id;
      // 添加特定class
      otdiv.setAttribute('class', 'wm_div_class');
      otdiv.style.pointerEvents = "none";
      if ((defaultSettings.watermark_position === 'fixed') && !defaultSettings.watermark_parent_node) {
        otdiv.style.position = "fixed";
        otdiv.style.top = "0";
        otdiv.style.left = "0";
        otdiv.style.zIndex = defaultSettings.watermark_zIndex;
      }

      //判断浏览器是否支持createShadowRoot方法
      if (typeof otdiv.createShadowRoot === 'function') {
        shadowRoot = otdiv.createShadowRoot();
      } else {
        shadowRoot = otdiv;
      }

      //将shadow dom随机插入body内的任意位置
      var nodeList = document.body.children;
      var index = Math.floor(Math.random() * (nodeList.length - 1));
      if (nodeList[index]) {
        document.body.insertBefore(otdiv, nodeList[index]);
      } else {
        document.body.appendChild(otdiv);
      }

    } else if (otdiv.shadowRoot) {
      shadowRoot = otdiv.shadowRoot;
    }


    //如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔
    if (defaultSettings.watermark_cols == 0 || (parseInt(defaultSettings.watermark_x + defaultSettings.watermark_width * defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1)) > page_width)) {
      defaultSettings.watermark_cols = parseInt((page_width - defaultSettings.watermark_x + page_offsetLeft) / (defaultSettings.watermark_width + defaultSettings.watermark_x_space));
      defaultSettings.watermark_x_space = parseInt((page_width - defaultSettings.watermark_x + page_offsetLeft - defaultSettings.watermark_width * defaultSettings.watermark_cols) / (defaultSettings.watermark_cols - 1));
    }
    //如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔
    if (defaultSettings.watermark_rows == 0 || (parseInt(defaultSettings.watermark_y + defaultSettings.watermark_height * defaultSettings.watermark_rows + defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1)) > page_height)) {
      defaultSettings.watermark_rows = parseInt((page_height - defaultSettings.watermark_y + page_offsetTop) / (defaultSettings.watermark_height + defaultSettings.watermark_y_space));
      defaultSettings.watermark_y_space = parseInt(((page_height - defaultSettings.watermark_y + page_offsetTop) - defaultSettings.watermark_height * defaultSettings.watermark_rows) / (defaultSettings.watermark_rows - 1));
    }

    var x;
    var y;
    for (var i = 0; i < defaultSettings.watermark_rows; i++) {
      y = defaultSettings.watermark_y + (defaultSettings.watermark_y_space + defaultSettings.watermark_height) * i;
      for (var j = 0; j < defaultSettings.watermark_cols; j++) {
        x = defaultSettings.watermark_x + (defaultSettings.watermark_width + defaultSettings.watermark_x_space) * j;

        var mask_div = document.createElement('div');
        var oText = document.createTextNode(defaultSettings.watermark_txt);
        mask_div.appendChild(oText);
        // 设置水印相关属性start
        mask_div.id = defaultSettings.watermark_prefix + i + j;
        //设置水印div倾斜显示
        mask_div.style.webkitTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.MozTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.msTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.OTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.transform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.visibility = "";
        mask_div.style.position = "absolute";
        //选不中
        mask_div.style.left = x + 'px';
        mask_div.style.top = y + 'px';
        mask_div.style.overflow = "hidden";
        //mask_div.style.zIndex = "9999";
        mask_div.style.zIndex = defaultSettings.watermark_zIndex;
        //mask_div.style.border="solid #eee 1px";
        mask_div.style.opacity = defaultSettings.watermark_alpha;
        mask_div.style.fontSize = defaultSettings.watermark_fontsize;
        mask_div.style.lineHeight = defaultSettings.watermark_lineHeight;
        mask_div.style.fontFamily = defaultSettings.watermark_font;
        mask_div.style.color = defaultSettings.watermark_color;
        mask_div.style.textAlign = "center";
        mask_div.style.width = defaultSettings.watermark_width + 'px';
        mask_div.style.height = defaultSettings.watermark_height + 'px';
        mask_div.style.display = "block";
        mask_div.style['-ms-user-select'] = "none";
        //设置水印相关属性end
        //附加到文档中
        shadowRoot.appendChild(mask_div);

      }
    }

  };

  //初始化水印，添加load和resize事件
  watermark.init = function (settings) {
    window.onload = function () {
      loadMark(settings);
    }

    window.onresize = function () {
      loadMark(settings);
    }

    if (window.addEventListener) {
      window.addEventListener('DOMContentLoaded', function () {
        loadMark(settings);
      });
    }

    // window.addEventListener('load', function () {
    //     loadMark(settings);
    // });
    // window.addEventListener('resize', function () {
    //     loadMark(settings);
    // });
    // window.addEventListener('DOMContentLoaded', function () {
    //     loadMark(settings);
    // });

  };

  //手动加载水印
  watermark.load = function (settings) {
    loadMark(settings);
  };

  //手动加载水印
  watermark.destroy = function (id) {
    if (id === undefined || id === null) {
      $('.wm_div_class').remove();
    } else {
      $('#' + id).remove();
    }
  }

  this.watermark = watermark;
  return watermark;
}));